What is coefficient of discharge in orifice meter?

Explanation: Coefficient of discharge (Cd): It is the ratio of actual discharge to theoretical discharge. As in a pipe, frictional losses are present therefore Qactual will always be less than Qtheoretical.

What is the formula for discharge coefficient?

In Equation (14.18) the discharge coefficient C d = ( 2 / 3 ) ( 2 g / 3 ) = 1.705 in metric units and, in Equation (14.19), C ′ d = ( 2 / 3 ) 2 / 3 = 0.544 in non-dimensional units. If the flow passes through critical depth over a weir crest then it might appear that Cd would always take that value.

Why is the discharge coefficient for the orifice meter far lower compared to the discharge coefficient for the Venturi meter?

Because of the sudden contraction at the orifice and the subsequent sudden expansion after the orifice, the coefficient of discharge C for the orifice meter is much lower than that of a venturi meter or a flow nozzle.

What is the value of coefficient of discharge for Venturimeter?

The discharge coefficient of a Venturi meter is typically 0.985, but may be even higher if the convergent section is machined.

What is the coefficient of discharge for a Venturi meter?

The effective discharge coefficient for venturi meters ranges from 0.9 to about unity (Streeter, 1951; American Society of Mechanical Engineers, 1983) with turbulent flow, and it varies with diameter ratio of throat to pipe.

Why Venturi meter VM coefficient is more than orifice meter OM coefficient?

In Venturi meter losses are less so coefficient of discharge is higher whereas in orifice meter due to no convergent and divergent cones there are more losses and hence its coefficient of discharge is less.In venturi meter losses are low due to steamline shape of the diffuser and the pressure gradient is not abrupt as …

What is a high discharge coefficient?

Properties of coefficient of discharge The value of Cd is high in nozzle measurement of flow, whereas its value is small in orifice measurement of flow. • It can be increased by lowering the convergent angle in flow measurement. It can also be increased when the pressure of working fluid is enhanced.

What is the range of coefficient of discharge?

0.61 to 0.79. 0.72 to 0.89.

What is the value of coefficient of discharge for Venturi meter and orifice meter?

The discharge coefficient of a Venturi meter is typically 0.985, but may be even higher if the convergent section is machined. Discharge coefficients for uncalibrated Venturi meters, together with corresponding uncertainties, are given in ISO 5167-1: 1991.

How do you calculate orifice?

Divide the flow of the liquid by the velocity of the liquid to determine the area of the orifice in square feet. In the above example, you would divide 8 by 2. The total area of the orifice would be 4 square feet.

How do you calculate the discharge coefficient?

The following equation can be used to find the discharge coefficient: Cv = ((39.693 * d^4) / ( H / (V^2 / 2g)))^0.5. You can plug in the pressure head along with the same flow and corresponding velocity (using Q=VA) to derive the discharge coefficient:

What is an orifice flow meter?

Introduction. An Orifice Meter is basically a type of flow meter which is used to measure the rate of flow fluids (mainly Liquids or Gases), using the Differential Pressure Measurement principle.

What is the orifice coefficient?

The orifice plate discharge coefficient (C d) is the ratio of the true flow to the theoretical flow and is applied to the theoretical flow equation to obtain the actual (true) flow.